Extension-ladder



(No Model.) 7 i a Sheets-Sheet 1.

J. F. MACK.

I EXTENSION LADDER.

N0. 5'70,939. Patented Nov. '10; 189613 J; P. MAOK.

EXTENSION LADDER.

3 Sheets 8heet 2.

(No Model.)

Patented Nov. 10, 1896.,

N5 Model.)

' 3 Sheets-Sheet 3. J. F. MACK. EXTENSION LADDER. NO. 570,939.

Patented Nov. 10, 1896.

UNITED STATES PATENT OFFICE.

JOHN F. MACK, OF LITTLE VALLEY, NEW YORK.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 570,939, dated November10, 1896.

Application filed June 25, 1895. Serial No. 554,007. (No model.)

To all whmn it may concern.-

Be it known that I, JOHN F. MACK, a citizen of the United States,residing at Little Valley,in the county of Cattaraugus and State of NewYork, have invented a new and useful Extension-Ladder, of which thefollowing is a specification.

This invention relates to extension-ladders to be used when it isrequired to reach an elevated point and which are chiefly designed forservice in connection with life-saving apparatus usually provided as apart of the equipment of the fire department of a city or town, and hasfor its obj ect to provide a structure which will be light and simple inits organization and which will admit of the ladder-sections beingquickly extended for use and folded into a compact form when the deviceis not in use, and which at the same time will admit of the ladder whenextended being moved to any required position and firmly braced afterbeing properly adjusted.

A further object of the invention is to combine with the ladder a basketor car and means for raising and lowering the same, whereby persons canbe readily reached from any window or opening in a burning building andlowered to the ground in safety, and to combine with said car or basketprovisions for steadying the same when at its highest position, so thata person may enter the car or basket without the dangers attendant uponthis class of devices Where the car is permitted to sway by hangingpendent from the end of the hoisting-rope.

A still further purpose of the invention is the provision of novel meanswhereby the ladder-sections can be raised and lowered from the groundand held at the required point of extension, the said sections beingmoved successively and the section reaching the limit of its projectionbeing locked and automatically freed from the actuating mechanism, whichimmediately is thrown in gear with the next ladder-section of theseries, so as to move it to the required limit.

The improvement consists of the novel features and the peculiarconstruction and combination of the parts, which hereinafter will bemore fully described and claimed, and

which are illustrated in the accompanying drawings, in which- Figure lis a perspective View of the improved ladder, showing it extended. Fig.2 is a sideelevation of the same, showing it reduced to a compact formand supplied with a forward truck. Fig. 3 is a detail view showing therelative disposition of the parts when the first movable ladder-sectionis at the limit of its upward movement and the actuating mechanism is ingear for extending the next or second movable section. Fig. 4 is acrossthe axle. Fig. 8 is a detail view of one of the extension-braces.Fig. 9 is-a detail View of a rung.

The ladder may be composed of any required number of sections, accordingto the height to which it may be required to extend the same, and, asshown, itis formed of three sections 1, 2, and 3, which are so relatedas to slide the one upon the other, and these sections are of graduatedwidths, so that they will nest together and enable the parts to occupy aminimum amount of space when the structure is reduced to a compact form.The side bars of the sections may be of wood or metal, wood beingpreferred for the sake of lightness and cheapness of construction. Theside bars of the sections 2and 3 will have metal plates 4 secured totheir lower edges,and the outer edge portions of these plates twillextend beyond the sides of their respective bars and operate inguideways 5, provided on the inner sides of the side bars of therespective sections 1 and 2, said guideways being formed between theopposing sides of metal strips 6 and 7 secured, respectively, to

the top edges and inner faces of the side bars of the said sections 1and'fZ. The metal strips 7 are L-shaped in cross-section, and aresecured in any suitable manner to the inner faces of the side bars, andthe flat metal strips 6 are firmly attached in any approved manner tothe edge portions of the said side bars. Any well-known means may besubstituted for the parts at, 6, and 7 to guide the ladder-sectionsintheir movements and maintain them in a fixed relative position at anypointin their movement. The rungs 8 are preferably tubular and havetheir ends 9 flanged and fastened by rivets to the side bars, therebyresulting in further lightening the structure and providing a ladder ofexceeding strength, inasmuch as the side bars are not perforated for thepassage of the ends of the rungs, as usuallypracticed in theconstruction of ladders for general use.

The ladder will be supported upon trucks 10 and 11, which may be of anysuitable construction to facilitate the transportation of the device tothe required point for using. The front truck 10 is detachably connectedin any desired manner, so as to facilitate the extension of the ladderwhen required. The rear truck is a permanent part of the device, andcomprises an axle 12, mounted in bearings 13, made fast to the side barsof the section 1, and supporting-Wheels 14, loosely journaled upon thespindles of the axle 12. A locking-lever is mounted upon the outer endof the axle and is provided on its outer face with a cam-surface 16,which is adapted to engage with the ordinary axle-nut 17 and secure thesupporting-wheel in locked relation upon its axle. It will be understoodthat each wheel 14: will be supplied with a locking-lever 15, so thatafter the ladder has been properly positioned the wheels can be securedfrom turning upon their respective axles.

A hand-wheel 18, sprocket-wheel 19, and toothed wheel 20 are securedtogether, so as to revolve as annit, and are mounted upon' one end ofthe axle 12 inside of the adjacent supporting-wheel 14. Ashaft 21 isjournaled in the side bars of the section 1 in proximate relation to thefront or upper ends thereof, and this shaft has a sprocket-wheel 22keyed thereto upon its projecting end and around which passes asprocket-chain 23, by means of which motion is transmitted from thesprocket-wheel 19 to the said sprocket-wheel 22 and the shaft 21.Pinions 24c are placed upon the shaft 21 and are adapted to mesh withrackbars 25, secured to the side bars of the section 2, so that in therotation of the shaft 21 the section 2 will be moved upon the section 1,so as to be extended or folded as required. A pinion 26 is keyed to theprojecting end of the shaft 21 and is adapted to mesh with acorresponding pinion 27 on the end of the shaft 28, journaled in theside bars of the section 2 near to its rear or lower end. Asprocket-wheel 29 is mounted upon the opposite end of the shaft 28 andsupports the lower end of a sprocket-chain 30, which is supported at itsupper end by means of a sprocket-wheel 31 on the projecting end of asection 2 near to their upper ends, and this shaft 32 is supplied withpinions 33, which are adapted to mesh with rack-bars' 34, secured to theside bars of the section 3.

The operation of extending the ladderis as follows: On rotating thehand-wheel 18 in the proper direction the sprocket-wheel 19 will becorrespondingly actuated and drive the sprocket-chain 23 and effect arotation of the shaft 21 in the manner set forth, and by means of thepinions 24 meshing with the rack-bars 25 the ladder-section 2 will beextended, and when it reaches the limit of its upward movement therack-bars 25 will become disengaged from the pinions 24 and the pinions26 and 27 will gear, and a further rotation of the shaft 21 will,through the meshing pinions 26 and 27, drive the shaft 28 and cause amovement of the shaft 32 through the gearing previously described, andthe pinions 33 on the shaft 32 meshing with the rack-bars 34 will resultin an extension of the section 3. It will be understood that where morethan two movable sections are employed the parts will be relatedsubstantially in the manner set forth herein, so that after one sectionhas been extended to its utmost limit its extending mechanism will bethrown out of operative relation and the provisions for operating thenext section of the series will be thrown in gear, so that in thefurther operation of the extending mechanism the said section to beextended will be operated in the manner set forth, as will be readilycomprehended.

In order to support the section extended to its utmost limit andmaintain the pinions 26 and 27 in meshing relation, a supporting c011-trivance has been devised to positivelyengage with and sustain the saidsection in its extended position. These provisions consist of arock-shaft 35, journaled in blocks 36, provided on the inner faces ofthe side bars of the section 1 and having short arms 37 near its ends tobe projected across the path of the side bars of the section 2, andhaving an intermediate arm 38, which is connected by means of a rod orwire 39 with an operating-lever 40, pivoted at one end to a rung of thesection 1 and extending within convenient reach from the ground. Catches41, of any desired construction, are provided and suitably disposed toengage with the free end of the lever 40 and hold the latter in eitherof its extreme positions. After the section 2 has been extended thelever 40 is operated and results in turning the rock-shaft 35 in itsbearings and projecting the arms 37 in the rear of the side bars of thesection 2, and if the pinions 26 and 27 are not fullyin mesh theengagement of the arms 37 with the lower ends of the side bars of thesection 2 will effect an upward movement of the said section 2, so as tobring the pinions 26 and 27 completely and opera tively in mesh andthrow the pinions 2i and shaft 32, journaled in the side bars of therack-bars fully out of engagement, so that the parts may operatesuccessfully in the manner designed.

A lever 42 is provided and adapted to engage with the toothed wheel 20,so as to secure the latter from further rotation in either directionafter the ladder has been properly extended, and this lever 42 iselbow-shaped and is fulcrum'ed at the elbow and has one memberterminating in a bent end to engage with the teeth of the wheel 20, andits opposite end extending within convenient reach to be grasped andoperated when required.

A bracket 43 is located at the upper end of the topmost section and issufficiently broad to provide a foot-rest to assist in the safealighting of a person from the ladder into the basket or car 44, and theouter end of this bracket is formed with a tubular guide 45. and

provided with a pulley 46, over which the hoisting-rope 47 passes, bymeans of which the basket or car 44 is raised and lowered. The basket orcar 44 may be of any desired construction and is a light framework ofwirenetting, and is provided with a vertical rod '48, centrally disposedand to which the hoisting-rope 47 is attached. This vertically-extendingrod 48 is adapted to enter the tubular guide 45, by means of which thecar or basket is steadied, so as to prevent any swaying movements of thesaid basket or car and to obviate the disastrous results frequentlyoccurring by reason of the swaying of the basket when a person isattempting to enter the same. A drum 49 is loosely mounted upon the endof the axle 12, opposite to that provided with the parts 18, 19, and 20,and it is provided with a hand-wheel 50, by means of which it is rotatedto wind up the hoistingrope 47, and with a toothed wheel 51, which isadapted to be engaged by a lever 52, similar in construction and for alike purpose to the lever 42. A brake-band 53 is supported at one end byhaving attachment to a block or the side bar of the section 1, and afterpassing half-way around a head of the drum 49 is engaged at its oppositeend with the end of a lever 54, by means of which the brake-band can bepressed closely against the peripheral edge of the drumhead'49, so as toregulate the paying out of the hoisting-rope 47 in the descent of thebasket or car 44.

Levers 55 are pivotally attached to the lower or rear ends of the sidebars of the section 1 and are provided with the usual handlatches 56 toengage with notched segments 57, by means of which the said levers areheld in the required located position, and

these levers are adapted to facilitate the erection of the ladder andthe steadying and bracing of the same afterbeing raised to the requiredposition.

The braces 58 for sustaining the ladder after it has been extended arepivotally supported or connected at their upper ends to the side bars ofthe section 1, and, as shown, are secured to the ends of a rod 59,journaled in brackets 60, attached to the said side bars and stays 61between the said rod and the braces 58 to hold the latter from outwarddisplacement. These braces 58 are extensible and comprise the sections62 and 63, the upper sections 62 having a series of teeth 64, which areengaged by dogs 65, pivoted to the lower sections 63, and which dogs areoperated by hand-levers 66, having connection therewith by rods 67,operating in guides 68, formed on the said sections 63. Springs 69 areprovided and mounted upon the rods 67, so as to hold the dogs inengagement with the teeth 64. The sections 63 have lateral extensions70, which are bent to embrace the edge portions of the sections 62 andby means of which the two sections are held in operative relation.

It will be seen from what has been said that the construction is simpleand easy of manipulation, also that the parts are readily accessible,and that the ladder can be used wherever it is required to reach anelevated point. The manner of operation is perfectly obvious from theforegoing detailed description, and many objects and advantages not setforth herein are obvious, and it is to be understood that in theembodiment of the invention to meet the various needs changes in theform, proportion, and the minor details of construction may be resortedto without departing from the principle or sacrificing any of theadvantages of this invention.

The braces 58 are supported in a folded position by means of hooks orcatches 71, made fast at their upper ends to the side bars pf thesection 1, as most clearly indicated in Having thus described theinvention, what is claimed as new is 1. An extensible ladder comprisingaseries of sections, actuating mechanism for extending the sections, andcomprising pinions disposed at opposite ends of adjacent sections andbrought together when the said sections are I extended, a cross-shaftprovided with short arms to engage with the section after it has beenextended, and a lever operatively connected with the said shaft to turnthe same, whereby its short arms are brought in positive engagement withthe said extended ladder-section to move the latter up to insure theengagement of the said pinions and maintain them in meshing relation,substantially as set forth.

2. In combination, slidable ladd er-sections, actuating mechanismcomprising a rack and pinion for moving the first adjustable section .ofthe series and for carrying the same be yond its operating mechanismwhen fully extended, a rack and pinion for the second ad justableladder-section of the series brought into gear with the said actuatingmechanism, and means for elevating and supporting the first adjustableladder-section when moved to a point beyond its actuating mechanism andat the same time bringing the second adjustable ladder-section in gearwith the actuating mechanism and maintaining the parts in operativerelation, substantially as set forth.

3. In combination, a series of slidable ladder-sections, the firstsection provided with a shaft near its upper end having a pinion, the.

next section having a shaft provided with a corresponding pinion at itslower end, and means for elevating or extending the movable section andthrowing its operating mechanism out of gear when the said section isfully extended and bringing the said pinions into mesh, substantially asset forth.

4. In an extensible ladder, the combination with a bracket provided witha guide, of a basket, or car, having rigidly secured thereto a Verticalrod to engage with the said guide and hold the car, or basket, in afixed relative position when elevated, substantially as set forth.

5. In combination, an extensible ladder, a bracket secured to the upperend thereof and provided with a pulley and a guide, a basket having avertically-extending rod adapted to enter and cooperate with the saidguide, a hoisting-rope, a drum provided with means for its rotation, atoothed wheel having connection with the drum, a lever to engage withthe toothed wheel to hold the drum against rotation in either direction,and a band-brake adapted to be applied to a head of the drum to controlthe speed of the latter during the descent of the basket, substantiallyas described.

6. In combination, a series of ladder-sections slidably related, therelatively-movable sections provided with rack-bars, shafts journaled inthe opposite ends of the sections and provided wit-h pinions to meshwith the rackbars, by means of which the said sections are extended,pinions on the shafts of adjacent sections and adapted to be broughtinto mesh when said sections are relatively extended to the limit oftheir movement, and a support adapted to be engaged with the section andhold it at the limit of its upward movement and maintain the saidpinions in meshing relation and the operating mechanism out of gear,substantially as setforth.

In testimony that I claim the foregoing as my own I have hereto aflixedmy signature in the presence of two witnesses.

JOHN F. MACK.

IVitnesses:

F. McMERRILL, A. C. STEPHENS.

